opencode: add OAC

opencode/context/development/backend/navigation.md

@@ -0,0 +1,57 @@
+<!-- Context: development/navigation | Priority: critical | Version: 1.0 | Updated: 2026-02-15 -->
+
+# Backend Development Navigation
+
+**Purpose**: Server-side development patterns
+
+**Status**: 🚧 Placeholder - Content coming soon
+
+---
+
+## Planned Structure
+
+```
+backend/
+├── navigation.md
+│
+├── api-patterns/              # Approach-based
+│   ├── rest-design.md
+│   ├── graphql-design.md
+│   ├── grpc-patterns.md
+│   └── trpc-patterns.md
+│
+├── nodejs/                    # Tech-specific
+│   ├── express-patterns.md
+│   ├── fastify-patterns.md
+│   └── nextjs-api-routes.md
+│
+├── python/
+│   ├── fastapi-patterns.md
+│   └── django-patterns.md
+│
+├── authentication/            # Functional concern
+│   ├── jwt-patterns.md
+│   ├── oauth-patterns.md
+│   └── session-management.md
+│
+└── middleware/
+    ├── logging.md
+    ├── rate-limiting.md
+    └── cors.md
+```
+
+---
+
+## For Now
+
+Use specialized navigation: `../backend-navigation.md`
+
+Also see: `../principles/api-design.md`
+
+---
+
+## Related Context
+
+- **Backend Navigation** → `../backend-navigation.md`
+- **API Design Principles** → `../principles/api-design.md`
+- **Core Standards** → `../../core/standards/code-quality.md`